Got a message from Brock's new owner last night. She mentioned that the farrier came out last week to treat a crack in his hoof and suspected that he might have a bit of seedy toe, but not severe (yet). He cut away the crumbly bit of wall and advised her to soak the hoof in copper sulphate solution every few days and to keep cleaning the crack and applying petroleum jelly. The vet is coming out next week to treat a bit of Queensland itch (midge bite reaction) that he's got, and she's going to speak with him about the seedy toe too. She was keen to get my opinion.
To me that sounds like a good plan given that the seedy toe isn't too bad at the moment, but I've not had any first hand experience of it. All I really know is it likes the dark and dirt so keeping it clean and allowing the light in is important. Do any of the hoof gurus here have any other advice?